Improvement in steam-boiler furnaces



.Improve-ment in SteamBoiler Furnaces'.

Patented Jan 2 Sheets--Sheet 2; E.. F. GRIFFIN.

lmprovement in Steam Biler Furnaces.

F N0 122,521.` l Patentedlam),1872.

UNITED EDGAR F. GRIFFIN, OF CHICAGO, ILLINOIS.

IMPROVEMENT IN STEAM-BOILER FURNACES.

Specification forming part 0f Letters Patent No. 122,521, dated January 9, 1872.

SPECIFICATION. To whom t may concern:

Be it known that I, EDGAR F. GRIFFIN, of Chicago, in the county of Cook and State of Illinois, have invented certain Improvements in Furnaces; and I do hereby declare that the following is afull, clear, and exact description thereof, reference being had to the accompanying drawing, which, together with the letters and figures marked thereon, form a part of this specification, and in which- Figure 1 is a longitudinal central vertical section of afurnace constructed with my improvements. Fig. 2 is a top or plan view of the gratebars and their connections. Fig. 3 is a transverse vertical section of the furnace.

Like letters of reference made use of in the several figures indicate like parts.

To enable those skilled in the art to make and use my invention, I will proceed to describe the same, with particularity, making use in so doing of the aforesaid drawing.

General Description.

A A are the walls of the furnace covered by the arch or top B. C are hollow grate-bars, communicating at the front with a tube or pipe, D, and at the rear with a cylinder,-G. A space, F, is left between the outer grate-bars C O' and the side walls of the furnace, and said side gratebars are prolonged upward, forming chambers E, extending' from front to rear ofthe furnace the ent-ire length of the gratebars. A series of small apertures, c, extend along the sides of the chambers E, opening in toward the lire, and the cylinder G is pierced in like manner by a series of holes, g, upon a level with the holes e, and a second series, j', upon the upper side of the cylinder. This latter series may be dispensed with if desired, and a narrow slot extending the entire length of the cylinder used instead. One end ofthe tube l) projects outside of the furnace, and is iitted with a funnelshaped open mouth, d, with the neck or aperture into the tube contracted to a less diameter than the tube itself. Within this funnel is inserted a nozzle attached to and communicating with a steampipe, H, extending from the threeway cock I, at which intersect the ,said pipe H, a supply-pipe, H', connected with the exhaust of a steam-boiler, and the pipe H", which enters a second funnel aperture, as will be presently explained'.

By means of the pipe H hot steam is blown through the nozzle into the funnel d, and acting in a manner analogous to the well-known steam water-injector, induces a current of air `to follow it with considerable force into the tube D, so that the hollow grate-bars, chambers, and cylinder are iilled with a mixture of heated steam and air mingled 5 while so contained the heat of the fire acts upon the compound and expands and superheats it. This highly-heated compound of air and steam, which assumes somewhat the nature of a gas, pressing equally in every direction in the manner of all iiuids, and prevented from escaping from the ingress-aperture by the pressure of the entering current, rushesforcibly out of the small apertures e g into the fire above the burnving coal, producing a double combustion, burning all that is combustible of the escaping products. The apertures g shoot their jets across the path of the escaping products on their way to the exit-flue J, while the apertures j' or the slot, if used, forms a second curtain of gasjet ting into the exit-flue, mingling with what isn left of the smoke, consuming it, and, by its upward force, assisting in the draught of the furnace. This latter series of apertures, or a slot in lieu thereof', may shoot, if properly arranged,

directly into the exit-iiue, if desirable, in case of a defective draught.

An inner cylinder, m, within and concentric to the cylinder G, is arranged and connected to a shaft, n, with a hand-wheel, o, at the outside of the furnace, so that `it may act as a damper to close or open one or both series of apertures f g at pleasure.

The object of making the grate-bars hollow is two-fold, first, to heat the contained mingled air and steam to a high degree, and second, to preserve the bars them selves from burning out and gathering clinkers. The contained air and steam takes up the heat and carries it off, leaving the bars themselves comparatively cool.

The spaces F at each side between the outside grate-bars and their superimposed chambers and the inside ofthe furnace walls are at all times filled with a current of live air arising from the ash-pit, so that the radiant heat from the fire is met by'this non-conducting curtain and carried back into the flame; the air rising to the double-arched root' is cast back downward into the center of the llames, producing` a reverberation, which greatly assists the coinbustion.

Alarge amount of pulverized coal and coaldust is found with all coal, and as this would be verylikely to fall through the grate unconsumed in the above operation, to prevent this diiiiculty the funnel is so constructed that the coal-dust will settle toward the center thereof and pour into the furnace in a narrow stream; and immediately under the openin g of the feed in g-fu nnel is a small tunnel-shaped aperture, (Z, similar in all respects to the aperture d above described. The third pipe H enters this funnel by means of its nozzle, and hot steam and an induced current of air are propelled into the furnace through this aperture. This current of air and steam scatters and carries the falling coal-dust in a spray to all parts of the re, and. a great portion of it is consumed before it gets to the level of the grate-bars. By means ofthe three-way cock the exhaust steam may be sent to either or both pipes H H or shut oi' e11- tirely, at pleasure.

Claims.

Having thus fully described the construction and operation of my invention, what I claim as new, and desire to secure by Letters Patent, 1s-

1. The combination of the hollow gratebars C C', chambers E, cylinder G, tube D having funnel-mouth d, substantially as specilied.

2. The combination of the funnel K, funnelmouthed aperture el', and steam-pipe H, substantially specified and shown, for the purpose of separating the coarse fuel from the tine.

3. The con'lbination and arrangement of the three-way cock I,stea1npipes H H H, funnelshaped apertures d (1.', funnel K, tube D, hollow grate-bars C C', chambers E, cylinders G on, substantially as specied.

4. The air-spaces F at the sides of the furnace, substantially as speciied and shown.

EDGAR F. GRIFFIN.

J. W. MUNDAY. (149) 

